A detailed theoretical analysis of the high-speed characteristics of InAs/GaAs quantum dot lasers is presented. The modulation bandwidth, relative intensity noise (RIN) and induced carrier concentration chirp of a tunnelling injection laser and excited-state emitting DBR laser have been studied and compared with a conventional laser and cross-gain modulated laser. The study shows that the excited-state emitting DBR laser demonstrates higher modulation bandwidth and lower induced carrier concentration chirp than the tunnelling injection laser.